Trichuriasis | Encyclopedia MDPI

Trichuriasis: Comparison

Please note this is a comparison between Version 1 by Kegan Romelle Jones and Version 2 by Lily Guo.

Trichuriasis is the clinical disease of animals infected with the parasite of the genus Trichuris. This review attempts to present information on Trichuris spp. infestation in neo-tropical rodents that are utilized for meat consumption by humans

agouti
lappe

1. Introduction

The neo-tropics is a geographical region located in the western hemisphere between the Tropic of Cancer and the Tropic of Capricorn. Geographical territories present within this zone include the southern parts of North America, all of Central America, the northern parts of South America, and all of the Caribbean^[1]. Animals that are present in this region can be categorized into three groups: imported domesticated animals^[2], domesticated animals originating from the neo-tropics^[3], and non-domesticated neo-tropical animals^[4]. For the purpose of this review, neo-tropical rodents that are included belong to the domesticated and non-domesticated groups. Domesticated neo-tropical rodents, such as the guinea pig, are utilized in South America for their meat and are reared in captivity to provide meat protein for rural villages. The guinea pig is able to utilize household waste and provide income and food for these communities^[5][6]. Neo-tropical rodents on the verge of domestication are the agouti, lappe, and capybara. These animals have been reared in captivity in South America and the Caribbean for their meat ^[1]. These animals have been able to breed in captivity: the agouti produces four offspring per year ^[7] the lappe produces two offspring per year^[8], and the capybara can produce eight offspring per year^[9][10]. These animals are ideal in that they can utilize local feed resources and are adapted to local conditions of high heat and humidity. The meats produced by these rodents are highly nutritious, with high protein values and low fat and cholesterol concentration^{[11][12][13][14]}.

The neo-tropics is a geographical region located in the western hemisphere between the Tropic of Cancer and the Tropic of Capricorn. Geographical territories present within this zone include the southern parts of North America, all of Central America, the northern parts of South America, and all of the Caribbean [1]. Animals that are present in this region can be categorized into three groups: imported domesticated animals [2], domesticated animals originating from the neo-tropics [3], and non-domesticated neo-tropical animals [4]. For the purpose of this review, neo-tropical rodents that are included belong to the domesticated and non-domesticated groups. Domesticated neo-tropical rodents, such as the guinea pig, are utilized in South America for their meat and are reared in captivity to provide meat protein for rural villages. The guinea pig is able to utilize household waste and provide income and food for these communities [5,6]. Neo-tropical rodents on the verge of domestication are the agouti, lappe, and capybara. These animals have been reared in captivity in South America and the Caribbean for their meat [1]. These animals have been able to breed in captivity: the agouti produces four offspring per year [7], the lappe produces two offspring per year [8], and the capybara can produce eight offspring per year [9,10]. These animals are ideal in that they can utilize local feed resources and are adapted to local conditions of high heat and humidity. The meats produced by these rodents are highly nutritious, with high protein values and low fat and cholesterol concentration [11,12,13,14].

Trichuris

spp., also known as whipworms, have parasitized many domesticated species, causing enteritis, diarrhea, and weight loss [15].

Trichuris

spp. adults live in the caecum and colon; this predilection site has occurred due to evolution. The life cycle is direct; eggs with characteristic bi-polar plugs are passed in the feces and take two to three weeks to become infective (

Figure 1) ^[16]. Animals become infected by the ingestion of infective eggs^[16]. However, there has been limited information on the effects of

) [16]. Animals become infected by the ingestion of infective eggs [16]. However, there has been limited information on the effects of

Trichuris

spp. on neotropical rodents (domestic and semi-domestic). Thus, the objective of this review is to summarize the species of

Trichuris that parasitizes these rodents, the effect of this parasite on these animals, and the zoonotic potential of this pathogen.

that parasitizes these rodents, the effect of this parasite on these animals, and the zoonotic potential of this pathogen.

Figure 1.

Life cycle of

Tichuris trichiura (taken from^[17]).

(taken from [17]).

2. Trichuris spp. of Veterinary and Public Health Importance

2.1. Trichuriasis of Man

Trichuriasis is one of the major infectious diseases of children in developing countries^[18].

Trichuriasis is one of the major infectious diseases of children in developing countries [18].

Trichuris trichiura is a major, soil-transmitted helminth targeted by the World Health Organization in their mass drug administration program for pre-school and primary school children in endemic developing countries^[18]. There have been several cases of trichuriasis reported in humans. In some cases, it has been due to three

is a major, soil-transmitted helminth targeted by the World Health Organization in their mass drug administration program for pre-school and primary school children in endemic developing countries [18]. There have been several cases of trichuriasis reported in humans. In some cases, it has been due to three

Trichuris

spp.:

T. trichiura

T. vulpis

, and

T. suis

. Humans have been infected with

T. vulpis, and the diagnosis was made based on the morphology of the eggs and vulva from an adult female^[19]. Molecular techniques were used on

, and the diagnosis was made based on the morphology of the eggs and vulva from an adult female [19]. Molecular techniques were used on

Trichuris

spp. egg present in feces to identify

T. suis

and

T. trichiura in human populations from Thailand^[20].

in human populations from Thailand [20].

T. suis

has been experimentally given to humans, and the author stated that feces were negative for

Trichuris eggs 40 days post-infection^[21]. Experimentally treated patients showed no symptoms of gastrointestinal distress^[21]. In contrast to the previous studies, Kradin et al.^[22] showed that iatrogenic infection with

eggs 40 days post-infection [21]. Experimentally treated patients showed no symptoms of gastrointestinal distress [21]. In contrast to the previous studies, Kradin et al. [22] showed that iatrogenic infection with

T. suis

resulted in a persistent active infection in man. Pathological findings from colonic biopsies showed several round helminths beneath the ileocecal mucosa epithelium [22].

Trichuris trichiura has human and non-human primates as its natural hosts^[23]. Mixed infections with various

has human and non-human primates as its natural hosts [23]. Mixed infections with various

Trichuris

spp. in humans have been documented. There have been cases of mixed infections with

T. vulpis

and

T. trichiura ^[24][25]. The identification of the species of

[24,25]. The identification of the species of

Trichuris spp. was based on the morphology of eggs^[24] and polymerase chain reactions of the helminth eggs ^[25].

spp. was based on the morphology of eggs [24] and polymerase chain reactions of the helminth eggs [25].

Trichuris trichiura

and

T. vulpis

was also found in the stool samples of dogs that roamed around the community. This shows that dogs are key to the transmission of

Trichuris spp. to humans, but further work needs to be done to validate this finding^[25].

spp. to humans, but further work needs to be done to validate this finding [25].

Infections with

T. vulpis have been reported in children and adults ^[19][26][27]. However, all cases of trichuriasis in humans caused by

have been reported in children and adults [19,26,27]. However, all cases of trichuriasis in humans caused by

T. vulpis have had some association with dogs, and the diagnosis was made based on morphology of eggs present in the feces. Clinical signs reported in humans are abdominal discomfort, epigastric pain, nausea, vomiting, diarrhea, and poor appetite^[24]. Patients with

have had some association with dogs, and the diagnosis was made based on morphology of eggs present in the feces. Clinical signs reported in humans are abdominal discomfort, epigastric pain, nausea, vomiting, diarrhea, and poor appetite [24]. Patients with

T. vulpis ^[24][26][27] and

[24,26,27] and

T. trichiura^[19] have been treated with mebendazole and albendazole with improvements of clinical signs ^{[19][24][26][27]}. However, in vivo studies on albendazole and mebendazole have shown little efficacy against

[19] have been treated with mebendazole and albendazole with improvements of clinical signs [19,24,26,27]. However, in vivo studies on albendazole and mebendazole have shown little efficacy against

T. trichiura^[28]. At 14 days post-treatment, there was no difference in the disease prevalence seen between treatments of patients with 400 grams of albendazole ^[28]. Therefore, alternative anthelmintic treatment against

[28]. At 14 days post-treatment, there was no difference in the disease prevalence seen between treatments of patients with 400 grams of albendazole [28]. Therefore, alternative anthelmintic treatment against

T. trichiura

should be investigated. Ivermectin has been used to treat

Trichuris

spp.; however, it is very ineffective, as these parasites have become resistant to this drug. However, due to the increased prevalence of anthelmintic resistance, the drugs used to treat trichuriasis should be done with caution.

2.2. Morphological and Molecular Identifications of Trichuris spp.

2.2.1. Morphological Identification of

Trichuris spp. in Pigs, Dogs, Cats, Humans, and Non-Human Primates

Morphological analysis of

spp. in Pigs, Dogs, Cats, Humans, and Non-Human Primates

Morphological analysis of

Trichuris

spp. has been used for identification within various host species.

Trichuris trichiura

infection has been investigated in humans, non-human primates, and pigs, but based on morphological analysis, the

T. trichiura found in humans and non-human primates were indistinguishable^[29]. In pigs,

found in humans and non-human primates were indistinguishable [29]. In pigs,

T. suis

was differentiated from

T. trichiura

, based on the lack of peri-cloacal papillae in adult specimens. In female specimens, there were no morphological differentiation between

T. suis

and

T. trichiura^[29]. Ruminants evaluated in India using morphological analysis identified

[29]. Ruminants evaluated in India using morphological analysis identified

T. ovis as the major parasite ^[30]. ^[

Further research was done in domestic cats in St. Kitts. Based on the size of the

as the major parasite [30].

Further research was done in domestic cats in St. Kitts. Based on the size of the

Trichuris

spp. identified, authors believed that it was

T. campanula

, but based on the vulva structure the authors confirmed it was

T. serrata

. In conclusion, the authors, identified the parasite as

T. serrata, but recommended that molecular studies must be done in order to reliably identify this parasite^[31]. In dogs, male and female adult

, but recommended that molecular studies must be done in order to reliably identify this parasite [31]. In dogs, male and female adult

T. vulpis could be identified based on nine parameters (including body length, length of cuticular processes, and width of body at tail part)^[32]. Male

could be identified based on nine parameters (including body length, length of cuticular processes, and width of body at tail part) [32]. Male

T. vulpis can be distinguished from other species by spicule sheath ornamentation (the dimensions of the spicule) ^[32].

Recently, the morphometric approach analyzing the adult worms and eggs of

can be distinguished from other species by spicule sheath ornamentation (the dimensions of the spicule) [32].

Recently, the morphometric approach analyzing the adult worms and eggs of

Trichuris spp. of non-human primates were analyzed^[33][34]. Morphometric data on the adult worms showed that features present in the females made them indistinguishable for species characteristics, but adult male worms may be used to differentiate

spp. of non-human primates were analyzed [33,34]. Morphometric data on the adult worms showed that features present in the females made them indistinguishable for species characteristics, but adult male worms may be used to differentiate

Trichuris populations^[33]. Geometric morphometric analysis is a new diagnostic tool that can be used to differential

populations [33]. Geometric morphometric analysis is a new diagnostic tool that can be used to differential

Trichuris spp. present in non-human primates. However, further data must be collected to determine the sensitivity and specificity of this diagnostic tool^[34]. Combination of various techniques, such as the use of molecular and morphological analysis, should be performed for confirmation of various

spp. present in non-human primates. However, further data must be collected to determine the sensitivity and specificity of this diagnostic tool [34]. Combination of various techniques, such as the use of molecular and morphological analysis, should be performed for confirmation of various

Trichuris

spp. [33].

2.2.2. Molecular Identification of Trichuris spp. in Domestic and Non-Domestic Ruminants

Molecular techniques have been used to identify various

Trichuris

spp. in their animals or human hosts. Such techniques have been applied to

Trichuris

spp. found in ruminants (both domesticated and non-domesticated). Four

Trichuris

spp.—

T. discolor

T. ovis

T. globulosa

and

T. skrjabini—have been identified as inhabiting the caecum and colon of ruminants^{[35][36][37][38][39][40][41][42][43][44][45][46]}. One of the major discoveries was the identification of

—have been identified as inhabiting the caecum and colon of ruminants [35,36,37,38,39,40,41,42,43,44,45]. One of the major discoveries was the identification of

T. globulosa

and

T. ovis as the same species by isoenzymes ^[35], using second, internally transcribed spacer ribosomal DNA (ITS2 rDNA)^[38] and ITS1-5.8S-1TS2 ^[37]. Further molecular analysis was done comparing

as the same species by isoenzymes [35], using second, internally transcribed spacer ribosomal DNA (ITS2 rDNA) [38] and ITS1-5.8S-1TS2 [37]. Further molecular analysis was done comparing

T. ovis

and

T. discolor, where the entire mitochondrial DNA (mtDNA) was analyzed^[42], and with the use of internally transcribed spacers 1, 2, and 16S, partial DNA sequencing (ITS1, 2, 16rDNA) was completed^[44]. Based on mtDNA and rDNA,

, where the entire mitochondrial DNA (mtDNA) was analyzed [42], and with the use of internally transcribed spacers 1, 2, and 16S, partial DNA sequencing (ITS1, 2, 16rDNA) was completed [44]. Based on mtDNA and rDNA,

T. ovis

and

T. discolor

can be classified as two different species.

Trichuris skrjabini

, found in small ruminants (sheep and goats), was characterized using isoenzymes [36], ITS1-5.8S-1TS2 [37], and cytochrome oxidase subunit 1 and mitochondrial 16S rDNA [39]. Authors have stated that

T. skrjabini

is an independent species but has close relations to other

Trichuris

spp. that parasitize small ruminants.

Trichuris discolor

has been identified in domestic ruminants with the use of molecular techniques; however, it was recently identified in wild ruminants, such as the roe deer (

Capreolus capreolus

), sika deer, (

Cervus nippon

), red deer (

Cervus elephus

), fallow deer (

Dama dama

), and mouflons (

Ovis orientalis musimon)^[43][44][45]. In wild ruminants,

) [43,44,45]. In wild ruminants,

T. discolor was identified with use of ITS1-5.8S-1TS2^[43][44][45], but in cattle different populations of

was identified with use of ITS1-5.8S-1TS2 [43,44,45], but in cattle different populations of

T. discolor

in Iran, Spain, and Japan were investigated using 16S partial gene mtDNA, as well as ITS1 and 2 [43]. Callejon et al. [43] noted that there were specific populations of

T. discolor

groups based on geographical location. The author noted that one reason may be due to two cryptic species of

T. discolor

from Japan and Iran, as well as another from Spain.

2.2.3. Molecular Identification of Trichuris spp. in Cats, Dogs, Pigs, Humans, and Non-Human Primates

Trichuris spp. has also been identified molecularly in pets, such as dogs and cats. In cats it is associated with typhlitis, which also occurs in other animals^[46]. Identification of

spp. has also been identified molecularly in pets, such as dogs and cats. In cats it is associated with typhlitis, which also occurs in other animals [46]. Identification of

T. serrata

(cats) and

Trichuris vulpis (dogs) was accomplished through the use of 18S rDNA (cats) and enzyme-linked immunosorbent assay (ELISA) and ITS1-5.8S-1TS2 (dogs)^[47][48]. Comparative genetic studies were done of the

(dogs) was accomplished through the use of 18S rDNA (cats) and enzyme-linked immunosorbent assay (ELISA) and ITS1-5.8S-1TS2 (dogs) [47,48,49]. Comparative genetic studies were done of the

T. vulpis

found in dogs and

T. suis

found in pigs (wild and domesticated). There was a difference seen in amplified ITS1-5.8S-1TS2 rDNA between the

T. vulpis

found in dogs and

T. suis

found in pigs. Interestingly,

T. suis

collected from wild pigs (

Sus scrofa scrofa

) and domestic pigs (

Sus scrofa domestica) showed no sequential genetic differences^[49].

) showed no sequential genetic differences [49].

Several non-morphological processes were used to identify

T. suis found in pigs using isoenzymes^[50], ITS 1 and ITS2 regions of rDNA ^[51], large mitochondrial subunits and ITS2^[52], and nuclear ribosomes (18S, ITS2)^[18]. Due to the zoonotic potential of

found in pigs using isoenzymes [50], ITS 1 and ITS2 regions of rDNA [51], large mitochondrial subunits and ITS2 [52], and nuclear ribosomes (18S, ITS2) [18]. Due to the zoonotic potential of

T. suis

and its morphological similarity to

T. trichiura previous molecular studies have been done in both human and non-human primates^[53][54][55].

previous molecular studies have been done in both human and non-human primates [53,54,55].

Trichuris

spp. was taken from pigs (wild and domestic) and non-human primates (

Colobus guereza kikuyensis

and

Nomascus gabriellae

) and analyzed by amplification of rDNA (ITS1-5.8S-1TS2). The authors confirmed that the

T. suis

found in pigs was genetically different from

T. trichiura

Colobus guereza kikuyensis

and

Nomascus gabriellae^[53]. Nissen et al. ^[54] conducted a similar study to Cutillas et al.^[53], but

[53]. Nissen et al. [54] conducted a similar study to Cutillas et al. [53], but

T. suis

and

T. trichiura

were identified in pigs and humans in Uganda. The gastrointestinal tract of pigs only contained

T. suis

, while in humans

T. trichiura

T. suis

, and a heterozygous type was identified [54]. This showed that the use of ITS 2 and β-tubulin allowed the identity of several species of

Trichuris

in humans to be highlighted.

The research done by Cutillas et al. ^[53]and Nissen et al.^[54] highlights the fact that humans and non-human primates may be infected with several species of

The research done by Cutillas et al. [53] and Nissen et al. [54] highlights the fact that humans and non-human primates may be infected with several species of

Trichuris

that are generally classified as

T. trichiura.

This was seen with

Trichuris

spp. samples taken from the wild Japanese macaques (

Macaca fuscata

), where the

Trichuris

spp. identified had genetic (18S rDNA) dissimilarity compared to those found in humans [56]. This new hypothesis sparked scientists to investigate this phenomenon at a molecular level (

Figure 2). Ravasi et al.^[57] investigated the genotype of human and non-human primates in Central Africa. Sequencing of the rDNA (ITS1-5.8S-1TS2) revealed two

). Ravasi et al. [57] investigated the genotype of human and non-human primates in Central Africa. Sequencing of the rDNA (ITS1-5.8S-1TS2) revealed two

Trichuris genotypes that infect both humans and non-primates^[57]. Ghai et al.^[58] found similar results to Ravasi et al.^[57], but three

genotypes that infect both humans and non-primates [57]. Ghai et al. [58] found similar results to Ravasi et al. [57], but three

Trichuris

genotypes were identified as circulating within human and non-human primates. Humans were infected with two genotypes: one genotype that was only common to human samples (Group 1), and another genotype that infected humans as well as non-human primates (black-and-white colobus (

Colobus guereza

), blue monkeys (

Cercopithecus mitis

), grey-cheeked mangabeys (

Lophocebus albigena

), l’hoest monkeys (

Cercopithecus lhoesti

), olive baboons (

Papio anubis

), red colobus (

Procolobus rufomitratus

), red-tailed guenons (

Cercopithecus ascanius

), and the chimpanzee (

Pan troglodytes

)) (Group 3). The intermediary group (Group 2) had a

Trichuris

genotype that affected non-human primates (black-and-white colobus (

Colobus guereza

and the red colobus (

Procolobus rufomitratus)^[58]. Furthermore, this new species of

) [58]. Furthermore, this new species of

Trichuris

was found in the Francois’ leaf monkey (

Presbytis francoisi

) and the

Colobus guereza kikuyensis using mtDNA, rDNA, and morphometry^[59][60].

using mtDNA, rDNA, and morphometry [59,60].

Figure 2. Phylogenic tree of Trichuris spp. (taken from Cutillas et al. [53]).

2.2.4. Molecular Identification Trichuris spp. in Rodents

Trichuris

spp. has been found in domestic livestock and pets, but there are also species that are specific to rodents. The initial molecular research that was done on the

Trichuris

spp. present in rodents focused on European rodents [61].

Trichuris muris

was identified in Murid rodents in Europe with the use of rDNA (ITS1-5.8S-ITS2). It was found that two lineages had occurred, due to geographical distribution. One was found in northern Spain to Denmark, and the other in the Southern Europe (Croatia, Romania, and Turkey) [61]. In recent years, several new species of

Trichuris arvicolae have been found in Arvicolinae rodents using multi-local enzyme electrophoresis^[62]and rDNA (ITS1-5.8S-ITS2)^[63]. Further investigations were done in the phylogeographic analysis of

have been found in Arvicolinae rodents using multi-local enzyme electrophoresis [62] and rDNA (ITS1-5.8S-ITS2) [63]. Further investigations were done in the phylogeographic analysis of

T. arvicolae

in Europe, using the mtDNA cytochrome subunit 1 gene (cox1) and rDNA (ITS1-5.8S-ITS2). Nuclear genetics (ITS1-5.8S-ITS2) suggest that

T. arvicolae

show two geographic and genetic lineages (Neoarctic and Palaearctic). Mitochondrial results gave further details into the Palaearctic region, giving three geographic and genetic lineages (Northern Europe, Southern and Eastern Europe, and Italy and France) [64].

Scientists also investigated

Trichuris

present in Sigmodontinae rodents in South America (Argentina). New species, such as

Trichuris novonae

, were identified based on morphological analysis [65]. Another species that was identified morphologically was

T. pardinasi

[64]. Based on molecular characteristics, using ITS2 (rDNA), a new species named

Trichuris bainae was identified^[66]. Molecular analysis using cox1 and mitochondrial cytochrome b (cob) on the

was identified [66]. Molecular analysis using cox1 and mitochondrial cytochrome b (cob) on the

Trichuris

spp. found in Sigmodontinae rodents found three clades corresponding to three different species, which were

T. pardinasi

T. bainae

, and

T. navonae)^[67]. Further to this,

) [67]. Further to this,

T. massoiai

was identified in

Holochilus chacarius

(Cricetidae: Sigmodontinae) using morphological mitochondrial (cox1 and cob) and nuclear (ITS2) markers [68].

Callejon et al. ^[41][69] investigated nuclear (18S, triose phosphate isomerase) and mitochondrial (cox1, cob1) genes from

Callejon et al. [41,69] investigated nuclear (18S, triose phosphate isomerase) and mitochondrial (cox1, cob1) genes from

Trichuris

spp. from nine various host species

(Colobus guereza kikuyuensis

Papio hamadryas

Homo sapiens

Sus scrofa domesticus

Capra hircus

Canis lupus familiaris

Bos taurus

Mus domesticus

, and

Myodes glareolus

) from Spain. The data show that

Trichuris

spp. could be divided in three clades: Clade 1 =

T. arvicolae

T. muris

, and

T.vulpis

; Clade 2 =

T. suis

T. colobae

T. trichiura

, and

. spp. ex

Papio hamadryas

; Clade 3 =

T. discolor

T. ovis

, and

T. skrjabini^[69].

[69].

2.3. Immunomodulatory Effect of Trichuris spp.

Trichuris spp. has been used in the treatment of gastrointestinal autoimmune diseases, such as inflammatory bowel disease, Crohn’s disease, and ulcerative colitis ^[70][71][72].

spp. has been used in the treatment of gastrointestinal autoimmune diseases, such as inflammatory bowel disease, Crohn’s disease, and ulcerative colitis [70,71,72].

Trichuris suis (pig whipworm) had been experimentally given to humans with no overt sign of gastrointestinal illness. The eggs produced from the feces remained constant, and only a low percentage of these eggs embryonated in vitro^[21]. Some authors also noted that treatment of patients with inflammatory bowel disease, ulcerative colitis, and Crohn’s disease with

(pig whipworm) had been experimentally given to humans with no overt sign of gastrointestinal illness. The eggs produced from the feces remained constant, and only a low percentage of these eggs embryonated in vitro [21]. Some authors also noted that treatment of patients with inflammatory bowel disease, ulcerative colitis, and Crohn’s disease with

Trichuris suis showed improvement in gastrointestinal signs, and in the management of disease the subjects were given ova every three weeks ^[70][71][72]. Surprisingly, Kradin et al.^[22] noted that a patient that underwent treatment for Crohn’s disease using

showed improvement in gastrointestinal signs, and in the management of disease the subjects were given ova every three weeks [70,71,72]. Surprisingly, Kradin et al. [22] noted that a patient that underwent treatment for Crohn’s disease using

T. suis

had adult worms beneath the ileocecal mucosal epithelium. This case does raise concerns about persistent infection from

T. suis

in man [22].

Further work was done on the use of excretory secretory products of

T. suis in rats^[73]. The investigation of the use of excretory products of

in rats [73]. The investigation of the use of excretory products of

T. suis

in swine epithelium cells was used as a model to be used in humans. It was noted that the excretory secretory products (ESPs) elicited the production of interleukin (IL)-6 and IL-10, which have been identified as anti-inflammatory cytokines that inhibit Th-1 responses. This proved that ESPs from

T. suis have immunomodulatory effects and can be used as candidates in the treatment of inflammatory bowel disease^[73]. The use of ESPs from

have immunomodulatory effects and can be used as candidates in the treatment of inflammatory bowel disease [73]. The use of ESPs from

T. suis

may be safer than the actual treatment with ova.

Subsequent research was done on the immunomodulatory and immunogenic effects of the proteins and ESPs of

Trichuris trichiura

and

Trichuris muris ^[74][75][76]. Proteins were analyzed from adult worm extract and fragments of

[74,75,76]. Proteins were analyzed from adult worm extract and fragments of

T. trichiura. These extracts and fragments were placed in cell cultures of human peripheral blood monocytes, and elicited the production of IL-10, IL-12, and TNF-α. Some fractions showed the inhibition of IL-5 production. The downregulation of IL-5 is a feature of a Th-2 response^[74]. Santos et al. ^[74] concluded that protein fractions of

. These extracts and fragments were placed in cell cultures of human peripheral blood monocytes, and elicited the production of IL-10, IL-12, and TNF-α. Some fractions showed the inhibition of IL-5 production. The downregulation of IL-5 is a feature of a Th-2 response [74]. Santos et al. [74] concluded that protein fractions of

T. trichiura

can be used in the treatment and prevention of allergic and autoimmune diseases. Immunogenic research was also conducted on the ESPs of

T. muris, and specific immunogenic proteins were identified. The structure of one such protein was Tm16, which was characterized and could be used in the production of a vaccine^[75]. Shears et al.^[76] noted that ESPs from

, and specific immunogenic proteins were identified. The structure of one such protein was Tm16, which was characterized and could be used in the production of a vaccine [75]. Shears et al. [76] noted that ESPs from

T. muris

elicited production of IL-9 and IL-13 when inoculated into rats. Eleven immunogenic proteins from the ESP of

T. muris

were also identified, and these could be used in the production of a vaccine [76]. Recent studies show that there is tremendous potential for

Trichuris

in human autoimmune disease, as well as vaccine development in rural countries where trichuriasis infections are prevalent.